The present invention relates generally to ignition coils for a spark-ignition internal combustion engine. More specifically, the invention relates to a circuit board for an ignition coil, and the electrical connection between components of the ignition coil.
Ignition coils typically contain the internal components such as a core assembly, a primary winding, a secondary winding, and at least one bobbin, all disposed within an ignition coil housing. The core assembly is typically constructed of steel lamination stacks upon which the primary and secondary windings of the ignition coil are mounted. The primary and secondary windings are typically comprised of copper wire and they are each wound around their respective bobbin. This secondary winding is in electrical connection with a spark plug, and the spark plug includes a pair of gap posts. The spark plug gap is located within the combustion chamber in order to ignite fuel and cause engine pistons to move downward in a power stroke, thereby powering the vehicle.
Ignition coils are also typically in electrical connection with a control means, such as a powertrain control module (PCM). One function of the PCM is to send pulse waves to a transistor that is in connection with the ignition coil in order to control the amount of current flowing through the primary windings. If the current flowing through the primary windings is suddenly interrupted, an electromagnetic field is induced in the secondary windings and causes a high-voltage current to flow across the spark plug gap and create the spark in the ignition chamber. Therefore, by controlling the timing of the pulse wave sent to the transistor, the PCM controls the ignition timing typically related to the angular position of the piston in the cylinder being fired.
Another function of the PCM is to run an engine at its maximum brake torque (MBT) spark timing in order to improve fuel economy. A related function of the PCM is to avoid knock, pinging, and misfire or partial-burn during the operation of an internal combustion engine. PCMs are typically in working connection with an MBT timing controller in order to determine and control the MBT timing, to limit misfire and partial burn, and to limit engine knock and pinging. One type of MBT timing controller accomplishes these functions by generating and utilizing ionization signals based on the current across the spark plug gap.
In order to create working electrical connections between the PCM, the transistor, and the MBT timing controller and in order to create working electrical connections within various components of each of these systems, electrical connectors are utilized. These connectors are typically leadframes comprised of metal such as brass or copper. The metal leadframes typically must be formed to a desired size and shape, often requiring multiple bends to the leadframes. Metal leadframes are typically relatively expensive due to the tooling and stamping operations typically used during manufacturing.
As seen from the above, it is desirable to provide an improved means of connecting the ignition coil internal circuitry and interior components to the exterior power supply and exterior controls.